As the light-emitting efficiency is increased and the cost of manufacturing is decreased, the dream for solid lighting device to replace the traditional lighting device may come true in recent years. Currently, the internal light-emitting efficiency of the light-emitting diode is about 50% to 80%, but a part of the light may be absorbed by the electrode or the light-emitting layer so the total light-emitting efficiency is degraded. Therefore, the mirror layer under the electrode has been provided to solve the problem. When the route of the light extracted from the light-emitting layer is blocked by the electrode, the mirror can reflect but not absorbs the light. On the other hand, the electrode has a bonding pad for wire bonding, and the bonding pad is usually made of gold (Au). Since gold (Au) is very expensive, the cost of the electrode is increased.